Moved author and date to boilerplate.tex.

Added copyright.tex to all files.
Added descr of check_interval to libsys.tex.
Corrected lotsa typos in tut.tex (thanks to George M. Sipe).
Corrected mktuple (should be newtupleobject) example in ext.tex.

Doc/ext.tex

@@ -2,14 +2,7 @@
 
 \title{Extending and Embedding the Python Interpreter}
 
-\author{
-	Guido van Rossum \\
-	Dept. CST, CWI, P.O. Box 94079 \\
-	1090 GB Amsterdam, The Netherlands \\
-	E-mail: {\tt guido@cwi.nl}
-}
-
-\date{14 July 1994 \\ Release 1.0.3} % XXX update before release!
+\input{boilerplate}
 
 % Tell \index to actually write the .idx file
 \makeindex
@@ -20,6 +13,8 @@
 
 \maketitle
 
+\input{copyright}
+
 \begin{abstract}
 
 \noindent
@@ -427,7 +422,7 @@ arguments, you must pass an empty tuple.  For example:
     object *result;
     ...
     /* Time to call the callback */
-    arglist = mktuple(0);
+    arglist = newtupleobject(0);
     result = call_object(my_callback, arglist);
     DECREF(arglist);
 \end{verbatim}